Biological Anthropology

1. Biological Anthropology Darwin, Mendel, and The Rise of the Synthetic Theory

2. Three Questions to Answer • Where does variation come from? • How is variation passed on from one generation to the next? • How is the variation present within a species at any time affected by the environment?

3. Science as arevolutionary process “normal” science scientific “revolution” anomalies

4. Normal Science ca. 1600the origin of living things • Great Chain of Being • Held in the hand of God • Ranked living things as more or less like God • Links represent species • Discrete • Immutable

5. Carolus Linnaeus1707-1778 • Son of a Lutheran pastor • Groomed to be a pastor • Preferred science • Became a physician and botanist Carl Linneausby M. Hoffman in 1734.

6. Carolus Linnaeus1707-1778 • Systema Naturae (1735, with many subsequent revisions) • Standardized names of plants and animals Binomial nomenclature Wedding Portrait of Linnaeus (1739)

7. Carolus Linnaeus1707-1778 Before, the common wild briar rose was known variously as • Rosa sylvestris inodora seu canina • Rosa sylvestris alba cum robore, folio glabro Using binomial nomenclature, names were standardized: • Rosa canina • Coffea arabica • Homo sapiens

8. Carolus Linnaeus1707-1778 • First believed species were immutable • Noticed hybrids • Observed that plant species could change appearance as they acclimatized to new areas • Eventually abandoned idea of fixity of species

9. Georges Cuvier1769-1832 • “Father” of comparative anatomy • Studied the anatomy of vertebrates • Established the field of vertebrate paleontology

10. Georges Cuvier1769-1832 • Noted distinct differences between fossil mammoth (top) and living Indian elephant (bottom) • Discovered that species could go extinct from Cuvier's 1796 paper on living and fossil elephants

11. What had happened to these animals? • Periodic “revolutions” or catastrophes had befallen the earth • These were events that had natural causes • Although Cuvier did not identify these with Biblical events, others would

12. Jean-Baptiste Lamarck1744-1829 • Studied the anatomy of invertebrates • Saw a relationship between an animal’s form and the way it exploited the environment • Argued that a change in the environment could affect the needs of the organisms in that environment, causing them to alter their behavior

14. Lamarck said • Altered behavior led to more or less use of a body part, which would therefore grow larger or smaller • Any such change could be inherited Trouble is… it’s wrong!

15. James Hutton1726-1797 • Scottish geologist • A cyclical “world machine” that exhibited “no vestige of a beginning – no prospect of an end.” • This view ultimately led to modern geological time scales

16. James Hutton1726-1797 • Pointed out role of erosion • Earth was timeless • A self-perpetuating place created for humans • No directional change, only cycles

17. Charles Lyell1797-1875 • Another Scottish geologist • Principles of Geology(3 Volumes; 1830-1833) • Argued that currently active principles were all that was needed to explain the geological history of the Earth

18. Charles Lyell1797-1875 uniformitarianism • Exclude the use of sudden catastrophes when explaining fossils • The earth was extremely old

19. Thomas Malthus1766-1834 • An Essay on the Principles of Population (1798) • Points out that more individuals are born into a species than will ever reach maturity • A struggle for survival

20. Thomas Malthus1766-1834 "population increases in a geometric ratio, while the means of subsistence increases in an arithmetic ratio." food supply population

21. Adam Smith1723-1790 • An Inquiry into the Nature and Causes of the Wealth of Nations (1776) • Laissez-faire economics: markets will perform best if they are allowed to function according to their own principles

22. Adam Smith1723-1790 • Smith’s ideas inspired Darwin in a more general way: • A system, once established, will run itself according to its own principles • A system does not require a higher authority to regulate a system itself

23. Charles Robert DarwinFeb. 12, 1809 – April 19, 1882 • father and grandfather were physicians • an avid insect collector from an early age • December 1827begins to study for the clergy at Christ's College, Cambridge • Graduates with Bachelor of Arts degree in April, 1831

24. Charles Darwin • Invited to serve as ship’s naturalist on H.M.S. Beagle

25. The Second Voyage of the Beagle Departs England on 27 Dec., 1831 – Returns to England on 2 October, 1836

26. The Post-Beagle Period • Darwin settles into a comfortable life • Publishes numerous books • Breeds pigeons

27. The Post-Beagle Period • 1838-1844 – serves as Secretary of the Geological Society of London • Becomes friends with Charles Lyell • 1837 - first mention of the “transmutation” of species in his notes From Darwin’s notes – ca. 1838

28. Alfred Russel Wallace • Studies the distribution of animals in the Malay Archipelago • Develops his own ideas about natural selection • Sends Darwin a manuscript in 1858 Alfred Russel Wallace(1848)

29. July 1, 1858 • Ideas of each presented at a meeting of the Linnean Society • both credited with the idea of natural selection

30. Darwin gets Busy! • Write “short” version of his ideas • Includes evidence from • His insights into insects and other organisms • Distribution of organisms • Fossil record • Embryology • Comparative anatomy • Comparative behavior • and, and, and Darwin at Down House,ca. 1880

31. November 24, 1859 • First edition sells out the first day • Acceptance in scientific circles is rapid • Makes no reference to evolution of humans ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION, OR THE PRESERVATION OF FAVOURED RACES IN THE STRUGGLE FOR LIFE. BY CHARLES DARWIN, MA., FELLOW OF THE ROYAL, GEOLOGICAL, LINNAEAN, ETC., SOCIETIES;AUTHOR OF 'JOURNAL OF RESERACHES DURING H.M.S. BEAGLE'S VOYAGEROUND THE WORLD.' LONDON : JOHN MURRAY, ALBEMARLE STREET. 1859.

32. From the final paragraph… “There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.”

33. Later Works • The Descent of Man, and Selection in Relation to Sex (1871) • The Formation of Vegetable Mould through the Action of Worms, with Observations on Their Habits (1881)

34. Keys Points of Natural Selection • At any one time, more individuals are born into a species than will survive • Each individual is unique (that is, different from the others) • Some of these differences may be advantageous in the environment in which the individual lives, while others may be disadvantageous • The individuals with the advantages are more likely to survive and reproduce than the individuals with the disadvantages • Over time, the advantageous traits become more common, and the disadvantageous traits become less common

35. Microevolution...and there’s nothing controversial about that Macroevolution…if the process continues long enough, you can end up with entirely new species And that’s what some people object to

36. Two Types of Selection Artificial Natural requires a trait to exhibit variation and a selective pressure requires • a trait to exhibit variation • and a selective pressure The selective pressure is exerted by the environment (nature) The selective pressure is exerted by humans

37. The Three Problems • How is the variation present within a species at any time affected by the environment? Darwin • How is variation passed on from one generation to the next? • Where does variation come from?

38. The Next Piece of the Puzzle Gregor Mendel and The Mechanisms of Inheritance

39. Gregor Mendel1822-1884 • Entered the Augustinian monastery of St. Thomas at Brnø at 22 • Ordained as priest in 1847 • Taught secondary school science

40. Two ideas about inheritance Particulate If you bred a white-flowered plant with a red-flowered plant, you will obtain a plant with either white or red flowers Blending If you bred a white-flowered plant with a red-flowered plant, you will obtain a plant with pinkish flowers

41. Pisum sativum

42. What Mendel Discovered • Each plant contained two pieces of information for a particular trait • Some of these were dominant, some recessive • Each parent contributed only one piece of information to each of their offspring

43. Some terms… • Gene – unit of hereditary information for a particular trait • Allele – alternate form of a gene • Gamete – a sex cell (egg for females;sperm, pollen for males)

44. Pisum sativum genes alleles

45. Mendel’s First Law The Principle of Segregation Alleles exist in pairswhich are separated from one anotherduring the production of gametes

46. this means that… …the chances of any particular outcome can be predicted!!!

47. Inheritance occurs according tostatistical probabilities!

48. Mendel’s Second Law The Principle of Independent Assortment The distribution of alleles for one trait does not affect the distribution of alleles for another trait

49. Independent Assortment • Whether an individual inherited one particular trait from its father did not affect whether it inherited a different trait from the father as well • It’s a crapshoot!

50. The Synthetic Theory of Evolution Variation is passed down according to Mendelian principles and selected for or against according to Darwinian principles